This 3D-Printed Tennis Ball Launcher Keeps Dogs Entertained All Day Long

If you have an energetic dog, it can be difficult to keep them entertained and to give them the exercise they need. I have an Australian Shepherd myself and I have a hard time giving him enough play time in between writing these articles for you all to enjoy. Fortunately, lots of dogs — mine included — love to play fetch and will happily chase balls until they collapse from exhaustion. But hurling those balls yourself can get tiring. That’s why Connor Bensor designed this fantastic 3D-printed tennis ball launcher that can keep dogs entertained for hours and now I want to build one for my pup.

This machine works a lot like the conventional tennis ball launchers that tennis players use for practice. Balls are dropped into the machine, which has wheels spinning at a high speed. As soon as a ball makes contact with those wheels, it is shot out for a dog to retrieve. But the tennis ball machines on the market today are fairly expensive; they start at around $300, which is quite a lot of money to spend on a dog toy. Benson’s machine can be built for far less by using affordable off-the-shelf parts. It doesn’t seem to be capable of shooting a ball as far or fast as a commercial tennis ball machine, but it is perfectly adequate for playing fetch with your dog in the backyard or a park.

The 3D-printed structure of this machine is quite simple and is roughly (ruffly?) the size of a tissue box. Balls are dropped in from the top and then rest on top of a stopper mechanism. An Arduino Nano board monitors an Adafruit proximity sensor next to that stopper. When a ball is detected, the friction wheels (which are also 3D-printed) are spun up using a pair of powerful Turnigy brushless DC motors that are controlled via Turnigy ESCs (Electronic Speed Controllers). Once the wheels are up to speed, the stopper mechanism is released by a small hobby servo motor. The ball then drops down into the wheels and goes flying. Power comes from a RC-style battery pack. It seems like this design would benefit greatly from the additional of a hopper, so multiple balls can be launched without a human needing to feed them to the machine. But even as it is, this machine is great for keeping good boys occupied and happy.